St205 Tyres

[cel_94]

Hopefully someone will have done this alreasy....I am about to change tyres, currently on the standard 215/50/16 Pirelli p700z's which are OEM on the car. However, toyota decided to fit a size of tyre that are only used on the GT4 and a ford probe! The problem being is that I want to change to Goodyear Eagle F1 or Bridgestone S03's but they do not come in the standard size. I know that changing size will have an effect on the rolling radius, but the two options I have are either 205/50/16 or 225/45/16. Has anyone changed to either size and what is the effect on grip and tramlining?

Any advice appreciated!

[Leeky]

You can go up to 225's and it will make little diffrence to your rolling.

Honestly, i've spent many hours, hundreds of pounds and buckets of sweat fiddling about with wheels and tyres.

As long as you dont change the wheel/tyre size too much it will make little diffrence.

If you look up "wheel size calculator" in google there are sites where you can input the tyre sizes and work out the diffrence.

Hope that helps.

:hokus-pokus:

[longhallage]

Tyre calculator

[cel_94]

Thanks guys, I know about the rolling radius and I agree, no big deal there, I am more concerned that if I go to 225s, the already comical tramlining will get worse and throw me into a ditch should I ever take my hands off the wheel! If I go to 205's, will this increase the level of understeer through less front end grip?

I know that both these tyre sizes may not make a huge difference to either grip or tramlining, but given that I'll have the tyres for at least 8000 miles, I want to make the right call.

[Leeky]

Bigger is always better.

[BrynO]

Having just looked into this myself, can tell you that standard sized Bridgestone RE010 or Pirelli 700Z can be had for about £100 a piece fitted. I have read some advice on tyre width which suggests stick to 215 for best combination of ride and handling on the GT-4, but like last poster says, the small jump to 225 prob does not make much impact. In the end I have decided to go to 17's but sticking with the 215 width on 45 profile. If you take that route you will find that 17" wheels in the 7.5" rim width are about as readily available as the standard tyres!

[cel_94]

Thanks guys. For info, I decided to go for 225/45/16 Eagle F1's. These are only available in the older GS-D2 pattern, but so far I am pleased. The lower profile makes the car seem to accelerate better, even allowing for the fact the speedo is now reading slightly over.... I'm sure its all in my mind though.